Worm-gearing.



M. MAAG.

l WORM GEARING. APPLICATION FILED AuG'.II.-I9I 4v1 Patented Aug. 6,1918.-

@ihwmwo 4- l?. fue y I l vinstance the index wheel of a gear vcutting machines requiring great accuracy, may

STATES PATENT crimen.

Max une, or aumen, SWITZERLAND.

worm-@Enma To all whom t may concern:y l

Be it known that I, MAX MAAG, a citizen of the Republic of Switzerland, residing at Zurich, in the Canton of Zurich, Switzerland, have invented new and useful Improve` ments in Worm-Gearing, 'of which the following is a 'specifications My invention relates to worm gearing, through which parts of machinetools, d1- viding engines, engraving machines, or othr e driven-or fed, and consists in the provision of means yfor eliminatin all back-lash, play, or lost motion between te coperating or intermeshin elements of such gearing.

This obJect is accomplished by providing an auxiliary worm, driving the same, or a similar worm wheel, as the main worm, said auxiliary worm being, itself frictionally driven so asto tend to move the carriage o r slideat a greater speed than the main worm.

r[his inventive idea is illustrated in two forms in the accompanying drawing, in which, v Figure 1 is a section through the preferred form of my improvement applied .the indexing mechanismof a gear-cutting machine, or the like, and Fig. 2 shows a modification of the mechanism of Fig. 1.

The principle of the invention will be i clearly understood from the following description ofthe parts. v

In' Fig. 1 15 indicates a wormewheel, for

machine of the inter-meshing generator type, said wheel being driven bythe 4worm 16 An absoluteabsence of lost. motion is ofthe highest importance, and is'obtainedy by the provision of a second'worm 17, meshingwith l5 and driven from the shaft 18r of the worm 16 through a pair of bevel gears 19, 20,- 'the latter of which is onlyconnected toits shaft b y-the friction clutch 21. Bevel gear 2 0 being smaller than 19, worm A17 always'tends to rotate the wheel 145 somewhatfaster than.

the' worm 16. Consequently, the wheel 15 is always held firmly between the two worms without any playv or lost motion and cannot make any undesirable movement under the inuence' of the workingpressure, however directed. A

Whenit is further desired to relieve the specification og-Leaers Patent. Patented Aug, 6, 19131, Application led August 11, 19g-14. Serial'No. 856,226.

" dividing .or index wheel from mechanical work, the' arrangement shown 1n F1 2 can be used. Herev is again saidw eel of, for example, ,a line dividing engine, and is driven by the main Worm 16. Onthe shaft 22 of the wheel 15 is mounted a second worm wheel 23, driven by worm 24 which is in turn' 'driven from shaft 18 of worm 16 through gears 25 and26 and friction clutch 27. Here again thepitch of the two worms noload thrown on'it, whereby its accuracy l remains unimpaired through long periods of use.

-It is to be noted that the work of rotatingthe worm wheel is performed by the friction drive alone, while the main -drive has only` to take care of the rate of movement. The main drive is,therefore, only loaded with the resistance offered by the friction clutchthroughwhich the wheelis driven, which resistance is, ening or loosening the clutch'.- Owing to this fact, this drive can be ve advantageously used in fine' dividing mac ines or indexing mechanisms.

Naturally, many other uses than those indicated can be made ofthe principle of .myl invention. It is' particularly useful for gear' and rack drives of all kinds where absolute freedom from 'lost motion or back lashis required. Having thus described my invention, what I claim is:

ofcourse, adjustable by-tight- 1. The combination with a source of power and a shaft to be driven therefrom, of a worm wheel 4on said shaft, a positively driven worm in mesh with saidwheel, a secconnectins, including a lfriction clutch, be-

ond worm also in mesh with saidwheel, and

tween the shafts of said worms, whereby the l second worm is driven faster than the first.

2. The combination with a source of power and a shaft to be driven thereby, of a worm wheel on` said shaft, a positivelyl driven vworm in mesh with said wheel, a second worm also in lmesh with'said wheel alud with my hand in4 presence of two slibscribing witits axis at right angles tothat of the rst Iresses. worm intermeshing bevel gears on the shafts v ofsaid worms, and an adjustable friction. v v MAX MAAG Y 5 clutch connecting one of said worms to its Witnesses: v

shaft. A. HEPrIJ, In te'stmony whereof I hayerhereunto set FREY. 

